drivers/nvmem/qfprom.c

   1 /*
   2  * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/device.h>
  15 #include <linux/module.h>
  16 #include <linux/io.h>
  17 #include <linux/nvmem-provider.h>
  18 #include <linux/platform_device.h>
  19
  20 struct qfprom_priv {
  21         void __iomem *base;
  22 };
  23
  24 static int qfprom_reg_read(void *context,
  25                         unsigned int reg, void *_val, size_t bytes)
  26 {
  27         struct qfprom_priv *priv = context;
  28         u8 *val = _val;
  29         int i = 0, words = bytes;
  30
  31         while (words--)
  32                 *val++ = readb(priv->base + reg + i++);
  33
  34         return 0;
  35 }
  36
  37 static int qfprom_reg_write(void *context,
  38                          unsigned int reg, void *_val, size_t bytes)
  39 {
  40         struct qfprom_priv *priv = context;
  41         u8 *val = _val;
  42         int i = 0, words = bytes;
  43
  44         while (words--)
  45                 writeb(*val++, priv->base + reg + i++);
  46
  47         return 0;
  48 }
  49
  50 static struct nvmem_config econfig = {
  51         .name = "qfprom",
  52         .stride = 1,
  53         .word_size = 1,
  54         .reg_read = qfprom_reg_read,
  55         .reg_write = qfprom_reg_write,
  56 };
  57
  58 static int qfprom_probe(struct platform_device *pdev)
  59 {
  60         struct device *dev = &pdev->dev;
  61         struct resource *res;
  62         struct nvmem_device *nvmem;
  63         struct qfprom_priv *priv;
  64
  65         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  66         if (!priv)
  67                 return -ENOMEM;
  68
  69         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  70         priv->base = devm_ioremap_resource(dev, res);
  71         if (IS_ERR(priv->base))
  72                 return PTR_ERR(priv->base);
  73
  74         econfig.size = resource_size(res);
  75         econfig.dev = dev;
  76         econfig.priv = priv;
  77
  78         nvmem = devm_nvmem_register(dev, &econfig);
  79
  80         return PTR_ERR_OR_ZERO(nvmem);
  81 }
  82
  83 static const struct of_device_id qfprom_of_match[] = {
  84         { .compatible = "qcom,qfprom",},
  85         {/* sentinel */},
  86 };
  87 MODULE_DEVICE_TABLE(of, qfprom_of_match);
  88
  89 static struct platform_driver qfprom_driver = {
  90         .probe = qfprom_probe,
  91         .driver = {
  92                 .name = "qcom,qfprom",
  93                 .of_match_table = qfprom_of_match,
  94         },
  95 };
  96 module_platform_driver(qfprom_driver);
  97 MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org>");
  98 MODULE_DESCRIPTION("Qualcomm QFPROM driver");
  99 MODULE_LICENSE("GPL v2");